If it turns off within 4min then your low on refrigerant, the compressor has to build up to around 16 bar then it gets pushed thru the condenser turning the gas into liquid as it cools then travels through the drier to remove any left over gas as you don't want gas going up to your tx valve, that 16bar then lowers to around 3 bars as liquid squeezes through the little hole and the liquid starts to boil going through your evaporator where your fan blows air through cooling the warm air down, then the liquid goes back to the compressor and starts over. something like that.
So until the pressure is reached it will keep running, so until the temp in the car has cooled down enough then you will see the compressor kick on and off to stop icing up the evap. If it was low on refrigerant then it will stop and start rapidly as it needs to wait for the liquid to return to pump before it can start.